3-D technique boosts hunt for breast cancer

A new technique for detecting breast cancer missed 40% fewer cases of the disease, according to preliminary results from a US trial in women at risk of the disease.

Stereo mammography, which allows doctors to view breast tissue in three dimensions, also resulted in half as many false positives - where doctors thought they had detected an early stage tumour but none existed.

"Standard mammography is one of the most difficult radiographic exams to interpret," said Dr David Getty, division scientist at BBN Technologies of Cambridge, Massachusetts, which is developing the new technology. "In a two-dimensional image of the breast, subtle lesions may be masked by underlying or overlying normal tissue and thus be missed, and normal tissue scattered at different depths can align to mimic a lesion, leading to false-positive detections."

The stereo technique is undergoing clinical trials in women who have an increased risk of breast cancer at Emory University Breast Clinic in Atlanta. It has not yet been trialled in the UK.

Initial results were presented to the annual meeting of the Radiological Society of North America in Chicago. Getty said that 1,093 women were given standard digital mammography screening plus a stereoscopic scan. In this case, two images are taken eight degrees apart and combined to give the 3D image.

Researchers looking at the scans flagged up 259 suspicious-looking findings for additional tests. Of these, 109 turned out to be tumours. The technique failed to identify 24 of the cases, while standard mammography did not spot 40 cases.